In a wafer-level lens process in which a plurality of lenses is arranged in a plane direction of a wafer substrate, it is difficult to obtain the shape accuracy or the position accuracy when the lenses are formed. For example, in a process of stacking substrates with lenses having lenses disposed therein to manufacture a stacked lens substrate, it is necessary to stack the substrates in a state in which the optical axes of the lenses stacked up and down are aligned with high accuracy.
PTL 1 discloses a technique of forming a step that is concentric to a lens in an outer circumference of each lens of a lens array to align the edges of the steps to thereby align the lens center and the sensor center with high accuracy during assembling of a sensor array in which a plurality of imaging elements is arranged in a plane direction of a substrate and a lens array in which a plurality of lenses is arranged in a plane direction.